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

Mentions 'Query discarded' indicating no persistence, but does not clarify other side effects or if it is purely read-only. Since no annotations are provided, the description carries the burden but is only partially transparent.

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?

One clear sentence, directly to the point, no unnecessary words.

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?

Given the nine parameters in the schema, the description fails to explain that the other eight are irrelevant. This leaves a significant gap for the agent to know which parameters are actually required. The description is incomplete for the tool's actual usage.

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?

The description does not specify that only the 'query' parameter is used. The schema includes eight other parameters with descriptions that appear to be decoys, but the tool description does not clarify that they are ignored. This can lead an agent to mistakenly provide irrelevant parameters.

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?

Clearly states the function: counts characters in a search query. The verb 'count' and resource 'search query' are specific, distinguishing it from sibling counting tools.

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 no guidance on when to use this tool instead of alternatives like memory-key-count or hn-front-count. No mention of appropriate context or exclusion criteria.

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