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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: it never live-crawls, returns compact chunks, and is a paid call with listed pricing. No contradiction with annotations.

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 dense, purposeful sentences with no filler. The central behavior is front-loaded, usage exclusions follow immediately, and cost is appended without bloating the definition.

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 read-only, two-parameter tool with an output schema and annotations, the description covers all essential decision points: what is searched, how results behave, when to use it, when not to, alternatives, and cost. Nothing critical is missing.

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 baseline 3 applies. The description does not substantially add to the schema, though the schema itself already provides helpful constraints like '2–8 keywords' and 'Not a stack trace'. No meaningful semantic gap remains.

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 action ('Keyword search') and a specific resource ('local Markdown index') scoped to four named frameworks. It clearly distinguishes itself from siblings by explicitly saying what it is not for: stack traces and copy-paste current syntax.

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?

Provides explicit when-to-use guidance ('concepts, symbols, or questions'), explicit when-not-to-use guidance ('Do not use for stack traces... or copy-paste current syntax'), and names the alternative tools for each case. Also gives actionable recovery advice via 'shorten the query' when hitCount is 0.

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