count

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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds context by naming the underlying function db.collection.count() and mentioning the optional filter, but does not disclose behavioral details like performance implications or that the count may be approximate in some MongoDB versions.

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 a single, well-structured sentence that front-loads the purpose. Every part is necessary, no redundancy or fluff.

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 tool's simplicity, the description provides adequate context for the core functionality. With an output schema present, return values need not be described. However, it could mention that the count is based on the query filter and note any MongoDB-specific nuances like approximate counts for large collections.

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% with descriptions for all three parameters. The description adds minimal value beyond the schema, only restating that query is optional and mentioning the underlying method. No additional parameter details like format or constraints are provided.

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?

Description clearly states it gets the number of documents in a MongoDB collection, specifies the underlying method db.collection.count(), and mentions the optional query filter. This distinguishes it from sibling tools like 'find' or 'aggregate' which return documents or perform aggregations.

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 for counting documents with optional filter, but does not explicitly state when to use this over alternatives like 'aggregate' for complex counts or 'find' for document retrieval. No exclusions or when-not-to-use guidance is provided.

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