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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower; the description adds real value by disclosing what the response contains per network — status, published link, network error, and stats that are null until read. It stops short of noting not-found behavior or rate limits, which keeps 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?

Purpose is front-loaded in the first clause, followed by return detail and then the routing sentence. The dense parenthetical on stats semantics is justified because there is no output schema, though it slightly burdens a single 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?

With no output schema, the description carries the return-value burden, and it does so by enumerating status, link, error, and stats fields. An agent has enough to call and interpret it; only failure/not-found handling is unstated.

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?

Only one parameter and schema coverage is 100%, so the schema already documents the id fully (including that it comes from schedule_post or get_schedule). The description repeats 'by id' without adding format or edge-case semantics, 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 ('Returns one post by id') and immediately scopes it as per-network results, which separates it from list-style siblings. The contrast with get_schedule makes the distinction unambiguous even 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?

Gives explicit triggers ('after publishing', 'when get_schedule shows a post as partial or failed') and names the alternative with its own condition ('use get_schedule instead to browse several posts'). This is a full when/when-not/alternative triad.

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