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

With no annotations, the description partially carries the burden. It states the output is a plain English explanation of ranking signals but does not explicitly confirm the tool is read-only or has no side effects. 'Explain' implies a safe operation, but more detail on behavior would be beneficial.

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 with no extraneous words. It front-loads the core action and details without waste.

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 explanation tool with no output schema, the description provides a high-level overview of the output (plain English explanation of signals). It covers the essential purpose but could more explicitly describe the return format (e.g., a string or structured text).

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%, so the baseline is 3. The description adds no extra information about the parameter beyond what the schema already provides (message_id is an ID from triage_inbox).

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 uses a specific verb ('explain') and clearly identifies the resource ('why a given message was surfaced') and the key signals (sender, urgency, commitment). It effectively distinguishes itself from siblings like 'triage_inbox' (listing) and 'list_commitments' (listing commitments).

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 the tool is for understanding ranking signals but lacks explicit guidance on when to use it versus alternatives (e.g., after listing messages in 'triage_inbox'). No exclusions or prerequisites are mentioned.

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