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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered. The description adds that it uses the Pythagorean theorem and mentions computed quantities (angles, area), but does not describe precision, error handling, or output format. With annotations carrying the behavioral burden, a 3 is appropriate.

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, but it is grammatically awkward and could be misread ('from exactly two measured sides, both acute angles, the right angle and area'). It is front-loaded with the main action but not optimally structured for clarity.

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 math tool with full schema coverage, rich annotations, and an output schema, the description adequately conveys the high-level purpose. The awkward phrasing around outputs (angles, area) introduces slight ambiguity that the output schema resolves, but the description is otherwise complete enough.

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 parameter meanings are fully documented in the schema. The description only restates that exactly two sides are required, which is already captured by the schema's oneOf and description. No additional syntax, format, or constraint details are provided beyond the 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?

States a specific verb 'Compute' and resource 'third right-triangle side' using the Pythagorean theorem, and mentions angles and area. The phrasing is slightly awkward but an agent can identify the tool's function from siblings that are mostly unrelated calculators.

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?

No explicit when-to-use guidance or alternatives. The phrase 'from exactly two measured sides' implies input requirements but is already covered by the schema's oneOf. There is no indication of when to use this tool versus other triangle-related tools.

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