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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true). The description adds genuinely useful context beyond them: the auth requirement ('Needs the user's Cotlet API key with access to this app'), the date-ordering of slots, and that each slot carries the ID other endpoints require.

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-loads the payload contents, then the ordering, then the parameter behavior, then the auth need. Every sentence carries information, though the sign-up slot field list is dense.

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 exists, and the description compensates by describing the return shape in detail (slots with fields, date order, count of wanted/filled). Auth and the key pruning/parameter behavior are also covered, leaving nothing an agent needs to call it correctly.

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 both parameters are already documented in the schema. The description restates open_only ('only slots that still have spots') without adding syntax or format detail beyond what the schema says, so 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?

States a specific verb (get) and resource (one sign-up) and enumerates exactly what is returned: description, link, and every slot's title, date, time, location, wanted and filled. This clearly distinguishes it from the sibling list_signups, which returns many sign-ups rather than one.

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 a concrete usage condition ('Set open_only to get only slots that still have spots') and implies this is the detail view for a single sign-up. It does not explicitly contrast with list_signups or other siblings, so it falls short of full when/when-not guidance.

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