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

Annotations already establish that this is a non-read-only, idempotent, non-destructive, open-world action. The description adds useful behavioral context: the heart can be taken back, the count is public, and the tool returns the heart count.

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?

The description is short and front-loads the core action, but the phrase 'For a heart; words go in a comment' is awkward and unclear, and 'The heart count is public... Returns its heart count' is somewhat redundant.

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 two-parameter toggle with no output schema, the description supplies the essential action, toggling behavior, public-count context, and return value. It could be clearer about comment interaction and permissions, but the main calling information is present.

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%, so both parameters are fully documented in the schema. The description reinforces that 'link' can be a link or code and that the action toggles a heart, but it adds little beyond the schema's own parameter descriptions.

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?

The description states a specific verb and resource: hearting an alarm or removing the heart via its link/code. It distinguishes the toggle behavior through 'on' semantics, though it does not explicitly compare itself with sibling tools such as post_comment.

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?

It implies usage by noting that hearts are tied to an alarm link/code and that words go in a comment, but it does not explicitly say when to use this tool versus post_comment or comment-related siblings. The guidance is present but requires inference.

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