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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds a useful permission-scoping constraint ('the authenticated user is allowed to view'), but says nothing about return shape, error behavior when the account is inaccessible, or not-found handling.

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?

One front-loaded sentence with the verb and resource first, no filler or repetition. It is efficient and appropriately sized for a one-parameter read tool.

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 single-object read with one fully documented parameter, annotations covering the safety profile, and no output schema to explain, the description supplies purpose, permission scope, and platform coverage. Nothing essential 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% for the single account_id parameter, so the schema already documents it fully. The description only echoes the 'any platform' framing found in the schema and adds no new syntax or format detail; baseline 3 is appropriate.

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 (Fetch) and resource (a single posting account), and specifies scope (accounts the authenticated user may view) and supported platforms (TikTok, Instagram, YouTube). The word 'single' implicitly distinguishes it from list-accounts-tool, 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 'a single ... account', so an agent can infer this is the one-account read versus list-accounts-tool, but there is no explicit when-to-use guidance, no mention of the alternative, and no stated preconditions beyond the permission note.

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