cos

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

No annotations provided; description accurately describes a pure mathematical computation with no side effects. Could mention return range but not necessary for standard function.

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?

Single sentence with no unnecessary words, directly conveys the tool's purpose.

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 simple one-parameter math function without output schema, the description fully explains what the tool does and what input is expected.

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?

100% schema description coverage; parameter 'number' is already explained in schema. Description adds no new meaning beyond stating radians, which is already in schema.

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 'Calculates the cosine of a number in radians' uses a specific verb and resource, clearly distinguishing it from sibling tools like sin, tan, etc.

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 usage for computing cosine, but does not explicitly state when not to use or mention alternatives. However, given simplicity, it is clear enough.

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