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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds a genuinely non-obvious behavioral trait the annotations cannot express: the billing model ('1 credit per record returned, minimum 2') and the resulting advice to keep page_size minimal. It stops short of describing rate limits or result shape, but the cost disclosure is a strong value-add.

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: purpose first, then the cost constraint, then the alternative-tool routing. No filler, and the most decision-relevant facts are front-loaded.

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 an output schema present the description need not explain return values, and annotations cover the safe-read profile. Combined with the filter list, cost model, and sibling routing, an agent has everything needed to call this correctly.

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%, so the schema carries the parameter burden and baseline would be 3. The description goes beyond it by tying page_size to a cost consequence, giving the agent a reason to tune that parameter rather than just its syntax, which nudges it above baseline.

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 ('Search') and resource ('stored public PitchBook fund profile records') plus the filterable facets (strategy, status, vintage, keyword). It also names the sibling tools it is not (funds_item, funds_facets), so an agent can distinguish 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?

Explicitly routes the agent: 'Use datasets_pitchbook_funds_item for one fund or datasets_pitchbook_funds_facets to inspect filter values.' This names both alternatives and the condition that selects each, which is exactly what usage guidance should do.

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