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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true), and the description usefully adds behavior beyond them: it discloses that the paywalled portion of your own posts is included, that images are returned as URLs, and that a Cotlet API key with access to this app is required. That is meaningful extra context, though it says nothing about rate limits or size 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?

Front-loaded with the return payload, then use cases, then auth need. Slightly redundant in restating the full-body-Markdown return twice, but every sentence contributes information and there is no padding.

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 steps up to describe the returned fields, the paywall behavior, and the image-URL convention, plus the auth prerequisite. It is nearly self-sufficient for invoking the tool; only the provenance of post_id is left to the schema.

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 post_id parameter is already documented ('Post ID from list_posts'), so the schema carries the load. The description adds no format or sourcing detail beyond what the schema states, which is the correct baseline of 3.

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+resource ('get' a 'post') and enumerates the returned payload (title, subtitle, body as Markdown, audience, URL, dates). The line 'Returns one post with its full body as Markdown' separates it from the sibling list_posts, and the paywall detail signals this is the full-content fetch rather than a stats/metadata call.

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 concrete usage contexts: 'Use it to edit a published post or to quote it in a Note,' which tells the agent when this content-retrieval call is warranted. It does not name a condition for when NOT to use it or explicitly route to alternatives such as get_post_stats, so it falls short of full when/when-not guidance.

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