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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the description does not need to repeat that. It adds valuable behavioral details: substring matching, case-insensitivity (in schema), and a 20-hit limit, which are not in annotations. It also clarifies that it searches claims and evidence, giving the agent a clear picture of the operation.

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?

The description is exactly two sentences: the first states the purpose, the second provides the matching behavior, the hit limit, and a usage tip. There is no fluff, and the most critical information is front-loaded. Every sentence contributes value.

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 lookup with two parameters and no output schema, the description covers the core behavior and limit, but it does not describe the format of the returned hits or what happens when there are no matches (beyond suggesting synonyms). The lack of output schema makes this a slight gap, but given the tool's simplicity, it is not severely incomplete.

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% and both parameters have descriptions in the schema (keyword: 'Substring to match...', workspace: 'Optional memory space...'). The description does not add new meaning beyond what the schema provides; it only repeats the substring concept. Thus, the baseline score of 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 clear verb ('look up') and resource ('what's known about a topic from prior work'), and specifies the matching mechanism (substring match across claims and evidence). It does not explicitly differentiate from siblings, but its functionality is distinct from the listed tools, so it earns a 4 rather than a 5.

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 description implies usage by saying 'Look up what's known' and offers a usage strategy ('Use literal terms first; if no hits, try synonyms'). However, it does not explicitly state when to use this tool versus alternatives, nor does it mention any exclusions, so it only meets the 'implied usage' level.

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