check_symmetry

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

Annotations already establish read-only, non-destructive, closed-world behavior, so the bar is lower. The description still adds real value by disclosing the default for `at` (bbox middle) and a context-dependent default for `tolerance` (0.005 m for objects >= 0.3 m, smaller for small ones) and noting the result echoes the value used.

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?

Three tight sentences, front-loaded with the core operation, then the two parameter defaults. Every sentence earns its place; only the somewhat compressed backtick phrasing slightly slows reading.

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 4-parameter tool with no output schema, the description covers the trickiest defaults but leaves `axis` semantics, the relationship between `axis` and `at`, and any detail of the returned answer unspecified beyond one clause.

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 0%, so the description carries the burden. It covers `at` and `tolerance` defaults well, but `axis` (the enum that `at` is measured along) is never mentioned, and `names` is only obliquely referenced as 'the objects'.

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 a specific operation (mirror vertices across a plane and count unmatched ones), which is precise enough to reveal that this is a symmetry analysis rather than a geometry edit. It does not explicitly differentiate itself from the sibling `mirror` tool, which an agent could easily confuse it with given the shared 'mirror' wording.

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?

Usage is implied by the name and the counting semantics, but there is no statement of when to use this versus `mirror`, `check_mesh`, or `check_contacts`. No exclusions or prerequisites are given.

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