marrow_agent_performance

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

No annotations are present, so the description must carry the full transparency burden. It discloses the type of data returned but does not describe behavioral details such as data aggregation, performance implications, or how the 'agent-facing' nature affects results. For a read-only tool, this is a minimal disclosure that raises questions about interpretation of the metrics.

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 core purpose and lists the returned metrics. Every word contributes meaning, with no filler or repetition. It is an excellent example of concise writing.

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?

The schema adequately covers parameters, but there is no output schema and the description does not specify the return format or data structure. It lists conceptual metrics but not exact field names or types, which could lead to parsing difficulty. Additionally, without usage guidance relative to similar sibling tools, the tool's role is not fully contextualized.

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 fully describes both parameters (period and agentId) with their defaults and constraints, so schema coverage is 100%. The description does not add additional parameter semantics beyond what is in the schema, so the baseline score of 3 is appropriate.

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 states the tool's function using a specific verb ('Get') and a specific resource ('agent-facing fleet value metrics'), and enumerates the metrics returned. However, it does not explicitly distinguish this from sibling tools like marrow_value_report or marrow_dashboard, so it stops short of 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?

No guidance is provided about when to use this tool versus alternatives such as marrow_value_report or marrow_dashboard. It does not state prerequisites, exclusions, or contexts where this tool is preferred, leaving the agent to infer appropriate usage from the name alone.

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