index_query

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

With no annotations provided, the description carries the full burden of behavioral transparency. It states the tool queries an in-memory index but does not disclose return format, ranking details, error behavior, or potential side effects. The description does not add meaningful behavioral context beyond what the one-sentence purpose states.

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 extremely concise, with one clear sentence followed by a structured parameter list. Every word earns its place, and there is no redundant information or filler. It is appropriately sized for a simple two-parameter 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?

Given the presence of sibling tools like 'search' and 'similarity', the description lacks essential context to differentiate use cases. It also provides no information about return values or expected output format, which is critical since there is no output schema. The tool is simple, but the description does not fully cover the operational context needed for correct 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 input schema provides only titles and types for the two parameters (query: string, top_k: integer), with no descriptions. The description adds minimal clarification ('The search query' and 'Number of results to return'), which is helpful but still basic. It does not explain default behavior, acceptable ranges, or edge cases, so it only partially compensates for the schema's lack of descriptions.

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 clearly identifies the action (query), the resource (in-memory index), and the outcome (most similar stored documents). It distinguishes from generic 'search' by specifying 'most similar', implying a similarity-based search. However, it does not explicitly differentiate itself from the sibling tool 'similarity', which could also involve similarity computations, so it is not fully differentiated.

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 provides no guidance on when to use this tool versus alternatives such as 'search' or 'similarity'. There are no explicit use cases, prerequisites, or exclusions mentioned. The context for when to select this tool is only implied by the phrase 'most similar stored documents'.

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