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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the safety profile is clear. The description's 'This writes to the backend' corroborates mutation but adds little new beyond the annotations. No mention of error behavior or whether notes are append-only vs overwriting.

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?

Two terse sentences, front-loaded with the action and resource. Every sentence earns its place with no filler.

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?

An output schema exists so return values need not be described, and annotations cover the write/safety profile. What remains missing is whether the zone must pre-exist and whether repeated notes overwrite or accumulate, a minor gap for such a simple tool.

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 50% — zone_id is documented in the schema with a format example, while note has only min/max length constraints. The description's 'short' hints at note brevity but adds no meaning beyond what the schema constraints convey.

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 and resource: 'Attach a short field observation to a zone.' This is clearly distinguishable from read-only siblings (list_zones, get_zone, rank_zones) by the write action. It doesn't name siblings explicitly, but the operation type makes selection obvious.

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 'short field observation' — an agent can infer this is for brief, zone-scoped notes. However, there is no explicit when-to-use guidance, no mention of alternatives, and no note about prerequisites (e.g., whether the zone must exist).

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 already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds a useful preview of the payload shape (score, drivers, field notes), but says nothing about not-found behavior or whether drivers/notes can be empty.

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, front-loaded with the verb and resource, with the returned content as a tight trailing clause. Nothing is padded.

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?

An output schema exists, so return values need not be detailed, and the single parameter is fully documented in the schema. Only the missing not-found/empty-section behavior keeps it from a 5.

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% with a single required parameter, and the schema itself supplies the 'Z-001' format example and regex pattern. The description adds no meaning beyond that, so the baseline 3 applies.

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 and resource ('Get one zone') and enumerates what comes back (score, drivers, field notes), which distinguishes it from list_zones by singularity. It never names the sibling explicitly, so the differentiation is inferential rather than stated.

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 singular 'one zone' plus the required zone_id implies this is the detail lookup after a list_zones/rank_zones call, but the description never says when to use it versus those siblings or what to do if the zone is unknown. Usage is 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 already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely new behavior in "best first" (sort order) and "candidate" (pre-filtered result set), but says nothing about result limits, pagination, or what happens with a null region. Useful but thin given the low bar.

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 sentence, zero filler, with the filter condition and sort order front-loaded. Every clause carries information the agent needs.

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 an output schema present and annotations covering the read-only profile, the description does not need to explain return values. The remaining gap is the unaddressed relationship to rank_zones and the absence of any result-size behavior, which leaves the agent guessing at boundaries.

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 both parameters carry their own descriptions ("Region filter", "Minimum score, 0-1"), so the schema does the heavy lifting. The description reinforces that min_score is inclusive ("at or above") but adds no format detail for region, so baseline 3 applies.

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 pairs a specific verb ("List") with a specific resource ("candidate drill zones") plus the qualifying condition ("at or above a score") and output ordering. It is distinct from get_zone by being plural/listing, but it never acknowledges rank_zones, which sounds closely related, so sibling differentiation is incomplete.

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 "at or above a score" implies the usage context (threshold-based candidate selection), which is more than nothing. However, there is no explicit when-to-use/when-not guidance and no routing to rank_zones or get_zone for agents weighing alternatives.

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 already cover the key safety profile: readOnlyHint=true and openWorldHint=false. The description adds that results are ranked and include a main driver, but does not expand much beyond that, which is acceptable given the annotation coverage and output schema.

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 purpose and output summary front-loaded. Every element earns its place with no filler.

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 output schema exists, annotations cover read-only and closed-world behavior, and the description explains that results are ranked with a main driver. It is complete enough for invocation, though the ranking methodology could be clearer.

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 top_n is already documented as how many zones to return. The description echoes 'top N' but adds no extra semantics such as ranking criteria or tie-breaking.

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 and resource: rank zones and return the top N for drilling, including each score's main driver. It is distinguishable from list_zones and get_zone by the ranking/prioritization purpose, though it does not explicitly name siblings.

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?

Implies the tool is for prioritizing which zones to drill first, but gives no explicit when-to-use guidance, prerequisites, or alternatives such as list_zones or get_zone. The usage context is inferable rather than stated.

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