Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only declare readOnlyHint=false, so the description carries most of the burden. It usefully discloses the side effects the agent may not expect — 3D Catmull-Rom route computation, commercial length-bin selection, and PoE/power DAG validation — which is real value beyond the annotations. However, it says nothing about batch atomicity (does one bad cable abort all?), what errors look like, or whether existing connections are rejected or overwritten.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

One dense sentence with the core action front-loaded and zero filler. The computed-output clause is informative rather than padding, though 'commercial length bins' is jargon an agent may not parse without domain knowledge.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a batch mutation with a deeply nested schema and no output schema, the definition covers what it does but omits failure semantics, whether the operation is all-or-nothing, and whether computed route/PoE results are returned or only persisted. Those gaps matter for an agent deciding how to sequence a multi-cable call.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, and the nested cable object's fields (cable_type enum, vlan_id, ip_cidr, face, preferred_portal_u) are all documented in-schema. The description only conveys the batch nature ('one or more cables') and the port-endpoint model, so it sits at the expected baseline without adding field-level meaning.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Specific verb+resource ('Connect ... cables between device ports') that an agent can immediately distinguish from the sibling disconnect_cables. The trailing clause also states what the tool computes (routes, length bins, PoE/power DAG), which sharpens the purpose beyond a plain write. It stops short of explicitly contrasting with disconnect_cables or validate_rack, so not a 5.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No explicit when-to-use, when-not-to-use, or alternative routing is given. The agent is left to infer that this is the create path versus disconnect_cables for removal and validate_rack for checking, and nothing is said about prerequisites such as whether the equipment must already be mounted.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The readOnlyHint=false annotation already signals a write operation, and the description adds that the blueprint is registered and persisted. However, it does not disclose duplicate-slug behavior, validation requirements, whether existing entries can be overwritten, or other operational side effects.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The definition is a single front-loaded sentence with no wasted words. It leads with the action and resource, then immediately adds the qualifying usage condition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The schema is extremely rich and fully documents the blueprint object, so the description need not repeat parameter details. However, for a complex write tool with no output schema, the description is minimal and omits workflow context such as how the registered blueprint becomes available to other tools or how conflicts are handled.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The single top-level parameter, blueprint, is documented with 100% schema coverage and extensive nested descriptions. The tool description adds no parameter-specific meaning, so the baseline of 3 is appropriate when the schema already does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific action and resource: 'Register and persist a custom hardware blueprint.' It also scopes it to 'unlisted equipment,' which implicitly separates it from sibling catalog lookup tools, though it does not name those siblings explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives a clear usage condition: use this 'when planning with unlisted equipment.' That tells the agent when this tool is appropriate, but it does not explicitly state what to do for listed equipment or name an alternative such as search_catalog.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The annotations already establish that this is not read-only, and the description adds useful scope by clarifying that instance_id causes ALL attached cables to be disconnected, which is a materially destructive bulk operation. However, it does not mention irreversibility, required device state, permissions, or partial-failure behavior for a mutation tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

One front-loaded sentence with no filler. Both modes are stated compactly and every phrase contributes to understanding the operation.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The core action is clear, but with zero required parameters the description should clarify what happens if both cable_ids and instance_id are omitted or provided together. For a destructive mutation with no output schema and minimal annotations, this leaves an important behavioral gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, and the schema itself describes both cable_ids and instance_id. The description restates their purpose but adds no extra semantics such as precedence when both are provided or behavior when neither is supplied, so it meets the baseline rather than exceeding it.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource ('Disconnect cables') and clearly covers both operating modes: by cable_id or by device instance_id. It is easy to distinguish from connect_cables, though it does not explicitly name that sibling.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description lays out the two usage modes directly: pass specific cable_ids to disconnect individually, or pass an instance_id to remove all attached cables. It gives clear context for selecting an input but does not state exclusions, prerequisites, or whether both parameters may be combined.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations declare readOnlyHint=false, so the agent knows this is a write operation, but the description adds nothing about what is written to disk, where, whether existing files are overwritten, or what happens if output_dir is omitted. For a file-emitting mutation tool with only a bare readOnlyHint, this leaves the behavioral profile under-disclosed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence with no filler, which is efficient. However, the terseness comes at the cost of leaving out two supported formats and any mention of the output directory.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a file-writing tool with no output schema, the description should signal the return shape (e.g. list of written paths) and write/overwrite semantics but does neither. Combined with the incomplete format enumeration, an agent cannot fully anticipate the effect of calling it.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so both parameters are documented structurally, giving a baseline of 3. The description lists four of the six format options (omitting carrier-scad and carrier-stl) and says nothing about output_dir, so it adds only partial meaning beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (generate/export) and enumerates the resource types produced (elevation SVG, wiring SVG, BOM Markdown, GLB). An agent can tell this is the output-generation step versus sibling tools like validate_rack or get_device_blueprint. It stops short of naming itself as the terminal step in the workflow.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no explicit guidance on when to call this versus siblings, or what prerequisites exist (e.g. must a rack be defined/mounted/validated first). The implied position at the end of a design workflow is left entirely to inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The readOnlyHint annotation already establishes this as a safe retrieval operation, and the description adds useful scope by naming the returned data categories. However, it does not mention error behavior for an unknown slug, rate limits, or other operational context, so the additional behavioral detail is modest.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single front-loaded sentence with no redundant or filler text. It communicates the action, target, and returned data efficiently.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple read-only tool with one fully described parameter and annotations covering safety, the description is largely complete. Because there is no output schema, it helpfully lists the returned data categories, though it does not describe the exact return structure or error cases.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The sole parameter is fully documented in the schema as an exact hardware catalog blueprint slug, giving a baseline of 3. The description's 'specific hardware slug' reinforces but does not add meaning beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Retrieve') and resource ('device blueprint') and enumerates the data returned, making the tool's purpose clear. It does not explicitly differentiate from siblings such as search_catalog or define_custom_blueprint, so it falls short of a 5.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The phrase 'for a specific hardware slug' implies the tool is used when an exact catalog slug is already known, but it gives no explicit when-to-use guidance, exclusions, or alternatives such as using search_catalog first. Usage is therefore only implied.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations declare destructiveHint=true and readOnlyHint=false, yet the description says nothing about overwriting an existing rack definition, losing previously mounted equipment references, or permission requirements. For a destructive mutation tool, this is a substantial gap; the description adds no behavioral context beyond the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single compact sentence with the key fields front-loaded and no filler. It could be marginally sharper by clarifying that the clearances refer to front/rear door clearances rather than 'enclosure clearances' as an abstraction.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

A 7-parameter destructive initialization tool with no output schema needs to say what state is created or replaced and how it relates to sibling setup tools. The description omits the overwrite consequence, defaults behavior, and ordering relative to mount_equipment, leaving the agent under-informed.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so every parameter (including enums and defaults) is already documented, establishing a baseline of 3. The description names some fields generically ('U height, rail depth, enclosure clearances') but adds no semantics beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (Initialize) and resource (rack) plus the configurable dimensions: standard, U height, rail depth, clearances. It is distinguishable from siblings like mount_equipment and validate_rack, though 'initialize' leaves mild ambiguity about whether it creates persistent rack state or just sets configuration.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No indication of when to call this versus siblings, and no prerequisites stated. The word 'Initialize' weakly implies a first setup step, but nothing tells the agent it must precede mount_equipment or that re-calling replaces prior configuration.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only declare readOnlyHint=false, so the description carries the burden of disclosing mutation behavior. It does mention cable-path recalculation, but omits the significant destructive default in the schema (remove_connected_cables=true means attached cables are disconnected on remove), and says nothing about reversibility or required preconditions.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

One sentence, zero filler, with the operation set and the side effect both front-loaded. Nothing is repeated from the schema or annotations.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For an 11-parameter mutation tool with no output schema, the description is thin: it does not state what is returned, whether the operation is undoable via undo_redo, or that removal disconnects cables by default. An agent could call it correctly on the happy path but could easily trigger unintended cable deletion.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3. The description only echoes the action enum values and adds no meaning about parameter interactions, such as which fields apply to which action or how the aliases (new_hostname/face/u_position) relate to their base fields.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names three specific verbs (move, rename, remove) against a specific resource (an existing mounted device instance) and adds the side effect of recalculating 3D cable paths. The word 'existing' implicitly separates it from mount_equipment, though the sibling is not named explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied by the verb list: use it when a device is already mounted and needs to be repositioned, renamed, or taken out. There is no explicit when-not guidance and no routing to adjacent tools such as disconnect_cables, unmount, or undo_redo.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only declare readOnlyHint=false, so the description carries the bulk of disclosure. Saying it 'runs the 5-stage validation engine' usefully signals the call may be rejected, but it never says what is validated, whether the mount is atomic on partial failure, or what state is left behind after a failed stage.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence that names the actions first, then the validation side effect. No padding, though the '5-stage' detail is a teaser that earns its place only if the stages are explained elsewhere.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a mutating tool with no output schema, the description covers what it does and flags that validation runs. What is missing is failure/state behavior and the mutual exclusivity of the two mounting targets, which matters because 7 parameters must be supplied with 100% schema coverage but no cross-parameter guidance.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so all 7 parameters are already documented, establishing a baseline of 3. The description only adds the conceptual mapping of 'rack unit' to u_position and 'modular carrier slot' to parent_carrier_id/slot_id, with no conflict rules (e.g., that u_position and slot_id are mutually exclusive targets).

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (mount) and resource (device onto a rack unit or carrier slot), plus the two mounting modes. It is clearly distinct from modify_equipment and init_rack, though it never names a sibling to route agents away from an update path.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is only implied: mount when instantiate-ing a new device from a blueprint, and the choice between rack-unit vs. carrier-slot mounting is hinted at. There is no explicit when-not, no prerequisites (e.g., blueprint/parent carrier must already exist), and no pointer to modify_equipment for changing an existing instance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

readOnlyHint=true already tells the agent this is a safe read, so the bar is lower, yet the description adds almost nothing beyond the filter list. It does not state whether multiple filters combine with AND semantics, whether results are ordered or limited, or what an empty match returns.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence with the action first and the filter dimensions after; nothing is redundant or padded. It is efficient, though one additional clause on combination semantics would have earned its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a zero-required-parameter read-only filter tool with fully documented schema and annotations, this is adequate to invoke correctly. Gaps remain on result behavior (ordering, limits, empty results) which the description cannot defer to an output schema that does not exist.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, including enum values for category and form_factor, so the schema carries parameter meaning. The description merely re-lists those same fields in prose and adds no filtering semantics (combination logic, units, matching behavior) beyond what the schema already documents.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description gives a specific verb and resource ("Filter hardware blueprints") and enumerates the filter dimensions, which distinguishes it from get_device_blueprint (single lookup) and define_custom_blueprint (creation). It stops short of explicitly naming a sibling, but the search/filter intent is unmistakable.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No when-to-use guidance is given: nothing says whether this must be called before mount_equipment, whether an empty result set is expected, or how this differs from get_device_blueprint. The list of filters implies a search use case but leaves selection to inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description adds useful behavioral context beyond the single annotation: undo reverts the most recent mutation and redo reapplies a reverted mutation. However, it omits important mutation-related details such as whether the redo history persists, error behavior when nothing exists to undo/redo, or authorization constraints.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single, front-loaded sentence that defines both actions without any wasted words. Every clause earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple one-parameter tool with full schema coverage and no output schema, the description gives enough for an agent to call it correctly. Minor gaps remain around edge cases and mutation scope, but the core behavior is clear.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the single 'action' parameter already has an enum and a description explaining undo/redo semantics. The description mirrors that information rather than adding format details beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states specific verbs and resource: 'Revert the most recent rack state mutation' for undo and 'reapply a reverted mutation' for redo. It is clear enough to distinguish from sibling tools like mount_equipment or connect_cables, though it doesn't enumerate which rack mutations are covered.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied through the action enum and the phrase 'most recent rack state mutation', but there is no explicit guidance on when to use undo versus redo, prerequisites, or what happens when there is no history. No alternatives are discussed, though none of the listed siblings serve this purpose.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

readOnlyHint=true already tells the agent this is a safe read operation, and the description does not contradict that. It adds useful context that the solver is deterministic and that the output includes ASCII elevations plus self-correction remediation text, but says nothing about what happens on failure, whether all racks or just the current one are checked, or how large the ASCII output may be.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence with no filler; each clause adds a distinct output (solver run, ASCII plans, diagnostics). The phrase '5-stage deterministic constraint solver' is jargon the agent cannot act on, which is the only wasted bytes.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description must carry the return-value burden, and it partially does by naming diagnostics, remediation suggestions, and ASCII elevations. It leaves unclear what is being validated and whether the ASCII plan appears in the result or is a side effect, which matters for a validation tool the agent is expected to act on.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters, so the schema imposes no semantic burden and the baseline of 4 applies. The description correctly implies a no-argument, state-based invocation.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Names three concrete actions — run the constraint solver, generate ASCII front/rear elevation plans, return diagnostics with remediation — which is far more specific than a restatement of the name. The gap is that the object being validated is never stated: with zero parameters it presumably validates the current in-memory rack state, but the agent must infer that.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No when-to-use guidance, no prerequisites, and no mention of adjacent siblings like export_deliverables (which also produces deliverables) or init_rack/mount_equipment (which presumably must precede a validation run). The agent has to guess where this fits in the workflow.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.