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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is fully covered without the description's help. The description adds the shape of the payload by enumerating returned fields, which is genuinely useful given there is no output schema. It says nothing about ordering, pagination, or result size for what is presumably the full catalogue.

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?

A single front-loaded sentence that covers the resource, returned fields, and the one option; nothing is padded. It is written as a fragment rather than a sentence with an explicit verb, which costs a little 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?

With no output schema and only one optional parameter, the description carries its weight by listing the exact fields returned, so an agent knows what it gets without calling. Missing ordering and pagination details keep it from being fully complete.

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 with its example category values already does the work and baseline 3 applies. The description's 'Optional category filter' restates rather than extends the schema by confirming it is not required and that omitting it returns everything, which is a small but real addition.

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 states this returns every UsePhysics calculator and enumerates the returned fields (id slug, name, category, formula, inputs, page URL), which clearly separates it from calculate, get_constant and list_constants. The verb 'list' only appears in the title, and no sibling is named explicitly, so it stops short of a 5.

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?

'Optional category filter' implies that filtering is available but never states when to filter versus fetching all. There is no guidance on choosing list_calculators over calculate, or on what to do when a category returns nothing. Usage is inferable but not taught.

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