get_categories

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

Annotations already cover readOnlyHint=true and openWorldHint=true, so 'Read-only' is largely redundant; however 'no API key needed' adds an auth requirement not expressed in the annotations, and the sentence about grouping gives a useful hint at the response shape. It stops short of describing ordering, pagination, or stability of slugs, so it adds value but not richly.

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 short sentences, front-loaded with what is returned, followed by safety/auth notes and then routing. Every sentence carries distinct information with no padding.

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 and no parameters, the description compensates by describing the return shape (grouped slugs with readable names) and the consumer workflow, which is everything 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?

The tool takes zero parameters, so the baseline of 4 applies; there is nothing for the description to disambiguate, and the schema is fully covered at 100%.

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 service category slugs) plus the returned shape (grouped into human services and AI-agent services, each with a readable name). This is distinguishable from siblings like get_platform_info or get_service_details without opening any 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?

Explicitly names the trigger ('when you need a valid `category` value') and the four downstream tools it feeds (search_services, search_workers, browse_jobs, create_job), plus an explicit alternative for a different need (get_platform_info for platform overview). Nothing is left to inference.

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