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

Annotations already declare readOnly/idempotent/non-destructive and closed-world, but the description adds meaningful scope the annotations cannot express: it never reads the user's repository, database or Vercel project, its content is quoted from viberaven.dev with a source link per part, and an unknown id returns found: false plus the list of known ids. That is exactly the behavioral detail needed to set expectations for a lookup 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?

Front-loaded with the trigger condition, then the return shape, then the negative scope and id list. Every sentence carries distinct information; nothing restates the title or name.

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 one-parameter read-only lookup, the description covers trigger, return content, non-capabilities, and error behavior. An output schema exists, so the brief return-value summary is supplementary rather than a gap, and nothing an agent needs to call this correctly 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% and the single gap_id parameter is fully described, so the baseline is 3. The description goes further by enumerating the eight known ids, giving format examples, and specifying the unknown-id failure behavior, which meaningfully guides valid input selection.

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 (explain) and resource (a VibeRaven finding id) plus concrete example ids (rls_disabled, env_var_drift), so the agent knows exactly what this returns. It is clearly distinguishable from launch_checklist and search_guides, which are action and documentation-lookup tools respectively.

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 crisp trigger conditions: 'Use this when the user asks what a VibeRaven finding id means ... or pastes a finding from a report,' which covers the realistic invocation contexts. It does not, however, name siblings such as search_guides as the alternative for general VibeRaven questions, so routing is clear but not fully disambiguated.

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