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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, and the description's 'Search' verb is consistent with them. The description adds genuinely useful behavioral context beyond annotations: quota accounting ('Counts toward your monthly searches. A batch counts as 1 call'), response size behavior (~4KB for 10 results), and the guarantee that behavior is unchanged from the deprecation. Minor omissions like rate limits or error behavior prevent a 5.

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?

Five short sentences, each earning its place: deprecation routing first, then purpose, default size, control knobs, pagination hint, and billing implication. No fluff or repeated schema content. Front-loading the deprecation warning is exactly what an agent needs before deciding whether to call this tool.

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 12-parameter tool with nested objects and no output schema, the description covers the essential operational facts: purpose, default response size, size control, total-count pagination signal, deprecation status, and quota cost. The return-value picture is partially left to the schema (e.g. newSince summaries), but the description fills the most critical gaps an agent faces. Not exhaustive enough for a 5given no output schema and 12 parameters.

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 92%, so the schema already documents nearly all parameters in detail. The description adds a small amount of cross-parameter guidance—that detail_level and max_results jointly control response size, and the ~4KB default scaling—but does not substantially go beyond the schema's already rich parameter descriptions. Baseline 3 is appropriate given the high schema coverage.

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 specific verb and resource ('Search grants, prizes, and foundations comprehensively') and immediately establishes its role as a deprecated alias of search_grantsplus, distinguishing it from the preferred sibling. An agent can tell exactly what it does and how it relates to its siblings without inspecting the 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?

The first sentence explicitly routes agents to the preferred alternative ('prefer search_grantsplus with a queries[] array, which now runs the identical batch fan-out') and states this tool exists only for backward compatibility. It also gives concrete control guidance: 'Use detail_level and max_results to control response size' and explains the pagination cue ('Response includes total available count so you can request more if needed').

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