Register metrics viewer

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

Annotations already indicate this is not read-only, not idempotent, and not destructive. The description adds that it registers a session for a host with tracking purposes, which is useful context, but does not disclose details about side effects, required host state, or error behavior. Given the annotations, the extra context is modest.

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 concise (two short sentences), but the first sentence mostly repeats the title. The second sentence adds purpose. No extraneous information, yet it could be more informative in the same length.

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 simple tool with one optional parameter and no output schema, the description still leaves gaps: it does not explain what a viewer session is, when registration is appropriate, or how hostId relates to the session. The minimal parameter hints and lack of usage guidance make it incomplete for an agent to invoke reliably.

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 0%, so the description must explain the hostId parameter. It only mentions 'for a host', which hints at host identity but does not clarify that hostId is optional, its format, or its meaning beyond the schema's integer type. This is insufficient for correct invocation.

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 specific action ('Registers a new viewer session') and its purpose ('to track who is viewing metrics'), clearly distinguishing it from sibling tools like unregister_metrics_viewer or update_viewer_heartbeat. The verb-resource combination is unambiguous.

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?

No guidance is given on when to use this tool versus alternatives such as updating a viewer heartbeat or unregistering a viewer. The description implies usage for starting a viewing session but does not explicitly state conditions or prerequisites.

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