ListMonths

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered by structured data. The description adds useful behavior only in the ordering rule ('newest first'); it says nothing about pagination or how the limit interacts with the plan scope.

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?

Two sentences, zero filler. The core purpose and returned fields are front-loaded, and the sibling routing is a compact second sentence.

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?

An output schema exists, so return values need not be explained, and the schema handles defaults and limits. For a read-only list tool with a sibling named for the alternate path, nothing an agent needs to invoke it correctly is missing.

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 both parameters (limit range 1-500, plan_id defaulting to 'last-used') are already fully documented. The description's 'newest first' merely echoes the schema's ordering note, adding no meaning beyond structured data. Baseline 3 applies.

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?

States a specific verb and resource (list monthly summaries for a plan) and enumerates the returned fields (Ready to Assign, income, assigned, activity, age of money). It explicitly distinguishes itself from the sibling GetMonth, so an agent can route without opening either schema.

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?

Names the alternative tool and the condition that selects it: 'Use GetMonth for category detail in a single month.' This gives clear routing guidance, though it does not state exclusions in the other direction or mention the ListPlans prerequisite for non-default plans (the schema does, however).

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