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

Annotations already declare the safe read-only/idempotent profile, so the bar is lower; the description nonetheless adds behavioral detail the annotations lack: alphabetical ordering, default page size of 25, and that results are catalog entries rather than per-member records. It does not discuss rate limits or pagination termination, but the essentials are covered.

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 tight sentences with zero filler, front-loaded with the use case, then return shape/paging, then the exclusion. Every sentence earns its place.

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?

Complete for a paginated read-only listing: scope, output contents, ordering, page size and the distinguishing exclusion are all stated, and an output schema exists so return-value detail need not be repeated.

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%, so gymId, limit and cursor are fully documented in the schema; description merely restates the 25-per-page default already in the limit parameter. Baseline 3 applies since the schema carries the parameter burden.

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 ('list...catalog service names with price and last edit time for one gym') and clearly separates itself from the gym-metadata siblings by scoping to services/prices. The closing clause distinguishes it from purchase/attendance lookups.

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 an explicit trigger ('when someone asks what their gym charges for a class, personal training session or other service') and an explicit exclusion ('Not for what a particular member bought or attended'). It does not name a specific alternative tool, though no sibling overlaps this catalog role.

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