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

Annotations already establish the safe/idempotent/read-only profile, so the description only needs to add semantics. It discloses the pass condition ('true if mission-ready') but the parenthetical 'always-33 score of 100' is cryptic jargon that an agent cannot decode, and the false condition and return format are left unstated.

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 that front-loads the action. Nothing is wasted, though the parenthetical clause reads as opaque internal jargon rather than clarification.

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 single-input validation tool with no output schema, the description conveys enough to call it, but it only describes the true/false meaning partially and leaves unclear what constitutes mission-ready or what a validation failure looks like.

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?

Only one parameter exists and schema description coverage is 100%, so the schema already documents 'content' fully. The description adds no syntax or format detail beyond it, which is the expected baseline when the schema carries the load.

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 ('Validate .faf YAML content'), and adds the meaning of the result ('true if mission-ready'). However it does nothing to distinguish itself from siblings like faf_analyze, faf_score, or faf_gate, which likely also operate on .faf content.

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 when-to-use guidance, no prerequisites, and no mention of alternatives. The agent is left to guess how faf_validate differs from faf_score or faf_analyze.

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