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

With no annotations, the description carries the full behavioral burden, and it does add real value: it discloses a mandatory cost/mechanism ($0.05 USDC on Base via x402), which is critical before invocation, plus an independence disclaimer. It falls short on the rest — nothing about determinism/randomness, whether the result is persisted, or what the response looks like.

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?

Three compact sentences, front-loaded with what the tool produces and followed by the two facts an agent must know (cost, disclaimer). The enum dump is somewhat list-like but each item maps to a real input value, so it earns its space.

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?

No output schema and no annotations, so the description alone must carry the definition — it covers purpose, formats, and payment, but leaves the seed parameter and the returned workout's structure/determinism unexplained. Adequate but with clear gaps for a 4-param tool at 0% schema description coverage.

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 0%, so the description must compensate, and it partially does: it spells out the format_type values (adding the useful gloss 'Engine (cardio)') and the style variants. It omits the seed parameter entirely, which is the one parameter whose semantics (deterministic vs random output) an agent most needs explained.

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+resource ('Workout generator (WOD)') and enumerates the supported styles and workout formats, so the resource is unambiguous. It does not, however, name any sibling to differentiate from get_todays_wod, coach_programme, or warmup_generator; 'instant' only implicitly signals on-demand generation versus retrieving a stored programme.

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?

'Instant' weakly implies this is for one-off generation rather than a stored programme, which gestures at when to pick it over get_weekly_programme. But there is no explicit when-to-use statement, no exclusions, and no named alternative, so the agent must infer the routing from the name alone.

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