Recommend GLM vs Opus for a task

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false. The description adds value by stating 'Free local advisory (no GLM call),' confirming no side effects and no cost, which aligns with readOnlyHint. It could also mention that input stays local, but the provided information is sufficient.

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?

The description is extremely concise (two sentences) and front-loaded with the core purpose. Every word earns its place, with no fluff. It achieves maximal information density in minimal space.

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?

Given the complexity (12 parameters, all well-described in schema) and the presence of sibling tools, the description is complete. It states that the tool is advisory and free, specifies the return format, and the schema covers all parameter semantics. No output schema is needed as the return format is described.

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 baseline is 3. The description does not add additional parameter semantics beyond what the schema already provides (e.g., '>20 forces Opus'). The schema descriptions are detailed and include decision-relevant hints. The description's summary of return values is useful but not parameter-specific.

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?

Description clearly states the tool's purpose: 'given a task profile, returns GLM-vs-Opus, model, confidence, and reasons.' It uses a specific verb ('recommend'), specifies the resource ('GLM vs Opus for a task'), and distinguishes from sibling tools like glm_agent and glm_delegate which are for actual execution, not advisory.

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?

Description explicitly says 'Call when unsure which engine to use,' providing clear context for when to use this tool. It does not explicitly state when not to use it or list alternatives, but the sibling tool names (glm_agent, glm_delegate, glm_status) imply they are for different tasks. A clear guidance with exclusions would improve it to a 5.

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