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

The annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: it states that the output is a vector graphic and that it is produced by a real computation engine rather than generated by an LLM, which tells the agent the result is reliable and reproducible. It says nothing about output format, how the artifact is returned, or any limits on the input, so 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?

The description is compact and front-loaded: it starts with the tool category in brackets, then gives the trigger condition, then the return value. The bracket label partly restates the title, but every clause still conveys something useful. Nothing is padded or buried.

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 3-parameter tool with no output schema, the description still leaves one real gap: it says the result is a 'vector forest plot' but not how that artifact is delivered (a file path, a base64 blob, a URL), and it does not say how many data items are allowed. The purpose and input requirement are complete; the output contract is not.

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 100%; every parameter, including the item structure {name, estimate, ci_lower, ci_upper}, is already documented in the schema. The description's mention of HR/OR/RR and confidence intervals helps map the user's effect-size vocabulary onto those fields, but does not add syntax or constraints beyond the schema. The baseline of 3 is correct.

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 gives a concrete verb and resource ('画森林图' / draw a forest plot) plus the required input condition: the user has HR/OR/RR values with confidence intervals. That is far more specific than the tool name alone. It never names a sibling or explains what makes it different from neighboring statistics tools (e.g. act_meta_egger, act_km_curve), so it falls 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?

The clause '用户有 HR/OR/RR 和置信区间，要画森林图' tells the agent exactly what situation triggers this tool: effect-size plus CI data and a request for a forest plot. That is clear when-to-use context. There are no explicit exclusions and no alternatives are mentioned, so it is not a 5.

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