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

The annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safe read-only behavior is covered. The description adds transparency about the data returned (current active job counts) and the fact that all sectors are listed. This extra detail about output content goes beyond the annotations, providing useful context about what to expect.

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?

The description is exactly two sentences, front-loaded with the core action ('List all recruiting sectors with their current active job counts') and followed by a practical usage tip. Every word earns its place; there is no redundancy or filler.

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 zero-parameter tool with an output schema, the description is fully complete: it identifies the resource (recruiting sectors), the data returned (active job counts), and how to use the results (slugs for the sector filter). It also implies 'all' sectors, setting expectations for the response scope. The output schema handles return value specifics, so no further description is needed.

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 has zero parameters, so the baseline for parameter semantics is 4. The description does not need to explain parameters, and it adds value by explaining the output (slugs and counts), which indirectly clarifies what the returned data means. No param information is missing.

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?

The description clearly states the tool's purpose with a specific verb ('List'), resource ('all recruiting sectors'), and adds scope ('with their current active job counts'). It also distinguishes the tool from siblings by mentioning the returned slugs are used for the 'sector' filter in search_jobs, making it clear this is sector-specific and not a general company or location listing.

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?

The description provides clear usage context by instructing the user to 'Use the returned slugs for the 'sector' filter in search_jobs.' This implies when to use the tool: whenever sector identifiers are needed for job filtering. It does not explicitly exclude alternatives like list_companies or list_locations, but the context is sufficiently clear for an agent to choose this tool over siblings.

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