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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds real value beyond that: return contents (messages, proposals, invoices, file names), ordering ('oldest first'), and an authentication requirement ('Cotlet API key with access to this app'). It omits pagination/volume limits, keeping it from a 5.

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?

Front-loaded and reasonably short, but wastes space repeating itself: 'oldest first' appears twice, and the payload list is given twice ('messages, proposals and invoices' then 'messages, the proposals sent in it, invoices raised and file names shared'). Tightening would improve it.

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 read-only single-resource fetch with annotations covering safety and no output schema, the description adequately conveys contents, ordering, auth needs and intended workflow. It lacks any note on result volume or pagination, so it falls just short of fully complete.

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% and the single parameter is documented as 'WorkStream ID from list_workstreams'. The description adds no further syntax or format detail, so this is the baseline-3 case where the schema does the heavy lifting.

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 (get one WorkStream) and enumerates exactly what is bundled in it: messages, proposals, invoices and shared file names. This clearly separates it from the sibling list_workstreams, which the schema also references as the source of the 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?

Gives explicit situational guidance: 'Read it before replying so your agent sees the whole history with this buyer.' That tells the agent when to reach for it. It stops short of naming list_workstreams as the alternative or stating exclusions, so 4 rather than 5.

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