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

Beyond the readOnlyHint/non-destructive annotations, the description discloses the returned payload (full text, URL, transcript, media, links, stats, collections), that missing content is NOT backfilled from the source platform, that an unknown or inaccessible id silently returns no save, and that calls count toward usage and are logged. These are exactly the operational facts an agent cannot get from structured fields.

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?

Four tight sentences: what it reads, how the id is obtained, what comes back, and edge-case behavior. Nothing is repeated from the schema and the scoping statement is front-loaded.

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-shape burden and does so by enumerating the returned fields and the absence of source-platform fetching. For a single-parameter read tool this leaves no material gap.

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 id parameter already names search_saves/recent_saves, so the baseline is 3. The description adds value by framing the id as one 'returned by a saves tool' and by describing the failure behavior for an unknown or inaccessible id.

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 ('Read one saved post in the authenticated user's AgentMash library') and scopes input to an id returned by a saves tool, which separates it from the list/search siblings. It does not explicitly differentiate from get_collection_saves, which also reads saves, so a 4 rather than a 5.

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 phrase 'using an id returned by a saves tool' establishes the precondition (obtain id from search_saves or recent_saves first) and implies this is the single-item follow-up to those tools. There is no explicit 'do not use this for X' exclusion, so it falls short of a 5.

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