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

Annotations already declare readOnlyHint=true, so the description doesn't need to re-establish safety; instead it adds 'Free', which is real behavioral information (no credit consumed). With no output schema, it also discloses the return shape (ok, quote fields, confirm_hint) and the downstream hand-off, which is context an agent cannot get from structured fields.

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 most decision-relevant fact ('Free'), then the workflow, then args and returns in a compact labeled layout. Phrasing like 'The price of making a plan' is slightly indirect, 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?

For a single-parameter, read-only estimate with a nested opaque plan object and no output schema, the definition supplies the missing pieces: cost model (free), input provenance, return shape, and the next-step hand-off. It stops short of explaining what 'fits', 'blockers', or 'warnings' mean in the quote, which would help an agent interpret the response.

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 is one parameter at 100% schema description coverage, and the schema already says the plan comes from ai_short_draft / ai_short_revise. The description's Args line repeats that verbatim, adding no new meaning such as expected plan structure or validation behavior; 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?

The description states a specific verb and resource: it prices ('The price of making a plan') an AI short, sourced 'from the server quote'. It is clearly distinct from the draft/revise/create siblings via the explicit chaining language, though it does not distinguish itself from other estimate tools such as music_video_estimate or studio_estimate_project.

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?

It gives concrete workflow routing: the input comes from ai_short_draft / ai_short_revise, and the returned quote.render_cents is passed to ai_short_create as confirm_cents. There are no explicit when-not-to-use conditions or exclusions against other estimate tools, but the intended position in the flow is unambiguous.

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