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

Annotations already cover readOnly/idempotent/non-destructive, and the description reinforces this with 'Spends nothing' and adds genuinely new context: the estimate follows the planes' price table while 'the gate is authoritative and a refusal names the exact price'. This warns the agent that the quote and the actual charge can diverge — useful, non-obvious behavior. It doesn't say what the response object looks like beyond `refused`.

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 benefit and the 'spends nothing' guarantee are well front-loaded, but the description then dumps the full 22-item enum inline, duplicating the schema and bloating an otherwise efficient statement. The price-rule clauses are valuable but delivered as a dense run-on.

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 no output schema, the description still conveys the return shape well enough: a credit estimate, an affordability answer, and a `refused` field indicating when the job would be rejected. For a two-parameter read-only tool this is close to sufficient, though the exact response fields are only sketched.

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 earns extra by explaining that `args` should mirror the job tool's arguments ('only the price-relevant ones matter') and by giving non-obvious pricing semantics — takes are free while voices cost one batch per ~6, and render_score parts are planned exactly as the job plans them. The detail is uneven, focused on only two of the 22 jobs.

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 ('Estimate what a job will cost in credits') plus the pre-condition timing ('BEFORE submitting it') and the affordability check. An agent can instantly separate this from doseedo_generate_music or any other job tool, which actually spend credits.

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?

Explicitly frames the use case as pre-flight pricing before invoking the job tool and reassures 'Spends nothing', which is the key decision input. It does not name a hard alternative (e.g. doseedo_account for balance) or state when-not to call it, so it falls short of a 5.

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