check_identity

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

With no annotations, the description carries the full burden; it does usefully disclose the computed outputs (master-colour share within a just-noticeable difference, missing colours, height/width drift). It omits whether the tool is read-only, how frames/layers are selected by default, and what form the results take.

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 dense sentences with the core action and metric list front-loaded; nothing is redundant or padded.

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 5-parameter tool with no output schema and zero schema descriptions, the definition explains what is measured but leaves frame/layer selection, the master_frame default of 1, and result formatting unexplained.

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 coverage is 0% across 5 parameters, so the description must compensate, and it only clarifies 'master' (accepting png or .aseprite). path, layer, frames, and especially master_frame receive no meaning beyond their bare titles.

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 (compare) and resource (every frame vs a master image) plus the exact metrics produced, so the intent is unmistakable. It does not, however, distinguish itself from the sibling tool 'compare', leaving the agent to infer the difference between a generic comparison and this identity check.

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 closing line 'The check that a character is still itself after animating' implies the use case well, but there is no explicit when-to-use/when-not guidance and no named alternative (e.g. 'compare' or 'check_animation') to route between.

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