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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so safety is known. The description adds vital behavior beyond that: it describes the NOT_FOUND error for unknown slugs and states that the error lists valid slugs, plus it explicitly enumerates the return fields and their absence. No contradiction with 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?

The description is long but every sentence earns its place: it front-loads the primary purpose, then explicitly ties usage to a sibling, explains parameter behavior, lists return fields, and closes with exclusions. It is well-structured and avoids redundancy with the schema's example by adding error-handling nuance.

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 single-parameter read-only tool with a full output schema, the description is remarkably complete. It covers what the tool returns (all key fields), what it cannot do (pricing, scheduling, application), and how it behaves on invalid input. Even though an output schema exists, the description's additional exclusions and error details ensure an agent will not misuse the 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 description coverage is 100%, so the schema already documents 'slug' with an example. The description adds extra value by explaining the consequence of an unknown slug (NOT_FOUND with valid slug list) and reinforcing that the slug must exactly match an existing path. This goes beyond the schema's static description, justifying a score above the baseline 3.

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 a specific resource ('full published detail of one VA Heroes PH Hero Path'), and distinguishes itself from the sibling get_hero_paths by clarifying it returns a single record identified by slug. It also states exactly when to use it ('after get_hero_paths when the user asks about one track'), making the purpose unambiguous.

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 explicitly says to use it after get_hero_paths when the user asks about a single track, and it enumerates what it does NOT return (pricing, schedules, enrolment, applicant data) and that it cannot submit an application. This gives an agent clear boundaries for when this tool is appropriate versus other siblings, even if alternatives are not all named.

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