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

Annotations only give the safety profile (readOnly=false, destructive=false, openWorld=true). The description adds real behavioral context beyond that: the effect ('frees the spot'), the per-call confirmation default, and the auth requirement (Cotlet API key with app access). Note the mild tension between 'cancel' and destructiveHint=false, though the 'frees the spot' framing lets it read as reversible rather than destructive.

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?

Purpose is front-loaded and the whole thing fits in a few sentences with no filler. The confirmation guidance ('you confirm each call; you can switch that off') and 'confirm with the user before each call' overlap somewhat, costing a little tightness.

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 two-param mutation with no output schema and annotations already covering the safety profile, the description covers purpose, effect, param sourcing, confirmation, and auth. It leaves unstated only edge cases like a not-found reservation or the return shape, which is acceptable given no output schema is defined.

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 100% and both params are documented in the schema, so the schema carries the semantic load. The description largely repeats the schema ('get reservation_id from get_class_roster') and only adds book_class as an alternate source, which is marginal added value.

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 ('Cancel a member's class reservation') and immediately disambiguates scope ('Cancels one reservation, which frees the spot'), cleanly separating it from the sibling book_class. An agent can tell what it does without reading the schema.

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?

Routes the agent to the correct prerequisites by naming get_class_roster and book_class as the sources for reservation_id, and describes the confirmation default. It stops short of explicit when-not-to-use conditions or naming a reschedule alternative, but the usage context is clear.

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