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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds meaningful context about access tiers: free returns a 12-month summary with YoY change, while full access unlocks up to 36 months of monthly data. This goes beyond annotation defaults by disclosing rate/access limitations and output granularity.

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?

Two sentences deliver the core purpose and key access-tier behavior without waste. The most important information (what and where) is front-loaded, and the optional filters are mentioned succinctly.

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, the description appropriately explains the return format (12-month summary with YoY vs monthly time series). It covers filters and access limits but omits minor details like the units of 'volume' (though implicitly job counts) and any potential pagination behavior. Overall, it is adequate for the tool's simplicity.

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 the schema already documents all three parameters. The description mentions role and country as filters and months via the access-tier discussion, but it does not add any new semantic detail beyond what the schema provides or clarify parameter formats beyond the schema's descriptions.

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 provides job posting volume trends on startup.jobs, with optional filters by role and/or country. This verb+resource+scope formulation distinguishes it from sibling tools like get_job (specific posting) and search_jobs (current listings).

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 implies this tool is for historical trend analysis, but it does not explicitly state when to use it versus alternatives or mention any exclusions. No sibling tool alternatives are referenced, so guidance is implicit rather than explicit.

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