telys_stats

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

Annotations already establish readOnly, idempotent, and non-destructive behavior lebensraum. The description adds meaningful behavioral context beyond those annotations: the operation fails when the collection does not exist, and the runtime-provided counters vary by runtime version. This gives an agent useful expectations about variability and failure without contradicting the annotation profile.

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 sentences with no filler. The core purpose and output contents are front-loaded, followed by routing guidance and then the requirement/failure caveat. Every sentence earns its place, making the description compact yet information-dense.

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 single-parameter read-only stats tool with no output schema, this description is complete enough. It explains what stats are returned, mentions version-dependent counters, states the practical use case, distinguishes siblings, and includes the failure mode. An agent has the information needed to select and invoke this tool correctly.

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%, and the input schema already documents 'collection' as the name of an existing collection. The description reinforces this by saying 'Required: collection' and noting the failure condition, but it adds little truly new semantic information about the parameter's format, possible values, or behavior. Baseline 3 is appropriate because the schema carries the full parameter documentation.

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 names a specific action ('Report stats') and resource ('one Telys memory collection'), then enumerates the output contents: name, partition key name, and live external-id count. It explicitly contrasts itself with telys_list_collections and telys_count, making its purpose unambiguous and distinguishable from siblings.

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?

It explicitly states when to use this tool: to confirm a collection exists and gauge its size. It also names alternatives and explains their narrower scope, with telys_list_collections enumerating collections and telys_count returning cardinality only. The required parameter and failure condition when the collection does not exist further guide invocation.

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