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

Annotations only declare readOnlyHint=true and openWorldHint=false. The description adds substantive provenance the annotations cannot carry: the trial counts come from a US ClinicalTrials.gov census that is 'deliberately kept separate from the multi-registry world index — never add the two together.' This prevents a real misinterpretation of the returned numbers, and is consistent with openWorldHint=false.

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 labeled blocks (USE WHEN / NEXT / IMPORTANT) make it scannable and front-loaded, and each sentence carries routing, scope, or data-caveat information. There is mild redundancy between 'headline picture' and 'This is a SUMMARY signal,' which keeps it from a perfect score.

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, the description must convey what comes back, and it does name the payload: overall and per-disease active trial activity plus the latest curated cure-research index. The 'include' section semantics (trials, research, stats) are left to the schema, a minor gap for a summary tool with a well-documented parameter set.

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% (limit, cursor, offset, disease, include are all documented inline), so the schema does the heavy lifting. The description only echoes the 'per disease' dimension and the sectioned nature of the payload; it adds no syntax, defaults, or pagination nuance beyond the schema. Baseline 3 applies.

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 concrete deliverable: 'the headline picture of cure progress: how much active clinical-trial activity exists overall and per disease, plus the latest curated cure-research index.' It explicitly frames itself as a 'SUMMARY signal' and names the siblings it differs from (search_world_trials for records, get_trial_landscape for field structure), so an agent can place it without opening any schema.

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?

Opens with an explicit 'USE WHEN' trigger and then routes with 'NEXT: for actual trial records ... call search_world_trials; for the structure of a field call get_trial_landscape.' Both the condition for using this tool and the alternatives for adjacent needs are spelled out, leaving nothing to inference.

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