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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the hierarchy shape being navigated and the no-argument default returning chapters. It stops short of disclosing deep-level behavior (e.g., what happens with an unknown part).

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 sentences, no filler. The hierarchy shape is front-loaded, followed immediately by the default no-argument behavior and the recommended use. 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?

With an output schema present and annotations covering the safety profile, the description supplies what's needed to invoke correctly, including the zero-argument default. The only meaningful gap is not clarifying its boundary against the overlapping list_parts sibling.

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 chapter/part/subpart semantics and the 'requires part' constraint are already documented in the schema. The description restates the hierarchy order but adds no format, valid-value, or error-handling detail beyond it. Baseline 3 is appropriate.

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 ('Navigate') and resource ('Title 38 hierarchy'), and enumerates the path shape (title → chapter → part → subpart) plus the listing behavior. It does not explicitly distinguish itself from the sibling list_parts, which appears to overlap in scope, so it falls short of the 5-level sibling differentiation.

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?

Gives a clear use case: 'Use this to discover valid parts/subparts before searching', which positions it ahead of search_regulations. However, it never names the overlapping sibling list_parts or states when browsing is preferred over it, so no explicit alternative is given.

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 safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds useful context about what comes back: heading, hierarchy path, issue date, and an ecfr.gov permalink. It does not mention error behavior for unmatched citations, but that is a minor gap given annotation coverage.

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 sentences, zero filler, with the core action front-loaded and the citation flexibility examples placed exactly where they are needed. 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?

An output schema exists so return-value detail is optional, yet the description still summarizes the payload, and it fully covers the single required parameter. Nothing essential for correct invocation is missing.

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 the baseline is 3, but the description genuinely adds meaning: it enumerates several citation spellings ("4.125", "§ 4.125", "38 CFR 4.125") and notes that appendix names like "Appendix A to Part 4" are also valid. That is richer than the schema's single example.

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 (fetch) and resource (full text of one Title 38 CFR section or appendix) plus the output format (markdown). This clearly separates it from siblings like search_regulations and browse_title38, which are browsing/search rather than single-document retrieval.

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 single-section scope and the accepted citation forms imply this is the right tool when you already know which section you want, but the description never states that explicitly nor names search_regulations as the alternative for discovery. Usage 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.

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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds real value beyond that: the semantics of each state, the remediation for 'empty' (run `cfr-free sync`), and the obligation to verify 'stale'/'degraded' results against the current eCFR. It does not mention latency or whether the check is cheap, so a 4 rather than a 5.

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?

Single front-loaded sentence that leads with the verdict concept, then defines each state inline. Dense with nested parentheses and em-dashes, which makes it slightly harder to scan, but no sentence is wasted.

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 the description need not explain return values, yet it still defines the four verdicts and their follow-up actions — more than enough for a zero-param read tool. The one gap is failing to clarify the boundary with the sibling 'index_status'.

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 there is nothing for the description to disambiguate; the baseline of 4 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+resource ('one-call readiness verdict for the local index') and enumerates all four possible verdicts with their meanings, so an agent knows exactly what comes back. It does not, however, distinguish itself from the sibling 'index_status', which sounds like an overlapping concept — that ambiguity keeps it from 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?

'Clients should gate queries on this before spending tool calls' gives an explicit when-to-use rule and even a cost rationale. It stops short of naming an alternative or a when-not-to-use case (e.g., after a sync is known to be fresh), and never mentions the similar-sounding 'index_status' sibling.

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 readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real behavioral context beyond that: the staleness verdict is computed relative to the CFR_MAX_AGE_DAYS threshold, and the report's components are named. It omits cost/latency and any permission notes, so not a full 5.

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 tight sentences with the content of the report front-loaded and the actionable instruction ('check this before relying on search results') placed last. No filler, no restatement of the title.

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 the description need not enumerate return values in detail, and annotations carry the safety profile. Combined with the stated staleness semantics and pre-flight usage advice, an agent has everything needed to call this correctly.

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 there is nothing for the description to disambiguate; the baseline for a no-parameter tool is 4. The description correctly implies the call needs no input.

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 ('Report how current the local Title 38 index is') and enumerates exactly what is reported: eCFR issue date, last sync time, row counts, staleness. This is clearly distinguishable from siblings like search_regulations or health without opening any schema.

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?

Gives explicit situational guidance: 'Check this before relying on search results,' which tells the agent when to reach for it. It stops short of naming an alternative or exclusion (e.g., versus the sibling 'health'), so it is clear context rather than full when/when-not routing.

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 readOnly, idempotent, non-destructive, and closed-world behavior, so the safety profile is fully covered. The description adds that results come specifically from the 'local index' and what fields are returned, but the return fields are already in the output schema, so the incremental behavioral disclosure 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?

Two tight sentences: the first states scope and return content, the second states the use case. Front-loaded and free of 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?

With a rich output schema and complete annotations, the description covers purpose, scope, and use case, leaving little for an agent to guess. Only minor details (ordering, whether the index can be stale/incomplete) are unstated.

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?

There are zero parameters, so the baseline is 4; nothing about parameter meaning needs documenting and the schema fully covers the (empty) input.

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 ('Enumerate') and resource ('Title 38 CFR part') scoped to the local index, and states the returned fields (structure-tree title, section/appendix counts). It is clear on its own, but it never names or contrasts with siblings like browse_title38 or search_regulations, which could plausibly overlap.

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?

'Use this to discover which parts are searchable' gives a concrete when-to-use condition tied to a downstream action. It stops short of stating when-not-to-use or pointing to an alternative sibling for related tasks, so it is clear context without exclusions.

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 safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds substantial behavior beyond that: bm25 scoring direction (lower is better), citation-pinning behavior with the `direct: true` signal and `inResults` flag semantics, and FTS5 phrase-query handling where only the last token gets a prefix wildcard.

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?

Front-loads purpose, then usage, then the citation-pinning and phrase-query nuances in roughly descending priority. Dense and largely waste-free, though the final FTS5 sentence is long and detailed enough to test the bounds of conciseness.

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, yet the description still explains the non-obvious return fields (bm25, direct, inResults) that an agent needs to interpret hits, plus pagination behavior on pinned citations. Nothing needed to call or interpret this tool is missing.

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 the baseline is 3, but the description adds real value: it explains `part` scoping with domain examples beyond the schema's terse 'restrict to one CFR part number', and describes how quoted `query` spans are tokenized into FTS5 phrase queries.

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 ('Full-text search across the local Title 38 (VA) CFR index using ranked keyword matching') and implicitly distinguishes itself from get_section, which it names as the follow-up for reading full sections. An agent can tell what this does versus its siblings without opening any schema.

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?

Gives clear usage context: use `part` to scope results (with concrete examples '4' for ratings, '17' for prosthetics) and follow up with get_section to read a hit in full. It stops short of stating when-not to use it versus browse_title38 or list_parts, so no explicit exclusions.

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