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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description goes further by disclosing accepted input families (plain IDs and gateway spellings such as openai/gpt-4-0613 or claude-3-opus@20240229) and the shape of the answer, including the negative case ('no retirement is listed').

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, front-loaded with the question the tool answers, then inputs, then return contents. No filler and every clause is informative.

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?

With no output schema, the description carries the return-value burden and does so: shutdown date, status, replacement, source, or an explicit 'none listed'. Combined with the input-format guidance, an agent has everything needed to call it 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 coverage is 100% and the single parameter is already documented, so baseline is 3. The description adds value the schema lacks: concrete examples of the multiple naming conventions the parameter accepts, which is the main practical ambiguity for this tool.

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 ('look up a model's retirement') and frames the exact question it answers (retired or scheduled for retirement). This clearly separates it from siblings like list_model_retirements and find_retired_models, which cover sets of models rather than one ID.

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 question form implies usage for a single model ID, and the mention of accepted ID spellings hints at when it applies. However, it never names an alternative or states when not to use it (e.g. prefer list_model_retirements for bulk listing), so routing is left to inference.

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