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

Annotations already declare readOnlyHint=true, so the safe-read profile is covered. The description adds the underlying Accelo API endpoint and the response envelope shape, which is useful context, but says nothing about error behavior (e.g., unknown id) or rate limits.

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?

Three short, front-loaded sentences with no filler. The raw endpoint line is arguably redundant for an agent using the MCP tool, which keeps it just short of a 5.

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 by-id getter with no output schema, the description supplies the response envelope shape ({ meta, response }) and the backing endpoint, which is enough to call it correctly. Missing only error/edge-case behavior.

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 the id and the _fields parameters are already documented in the schema. The description adds no format or syntax detail for _fields beyond what the schema provides, so the 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 ('Fetch a single prospect (sales opportunity)') and the parenthetical clarifies the domain term. The word 'single' implicitly separates it from list_prospects, but no sibling is named explicitly.

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?

Usage is implied by the presence of a required id parameter and the 'single' qualifier, so an agent can infer this is the by-id lookup versus the list tool. However, there is no explicit when-to-use guidance or statement of prerequisites/exclusions.

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