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

Beyond the annotations (destructiveHint=true, openWorldHint=true), the description discloses validation behavior (the key is checked against the remote Jira first, unknown/invisible keys are refused), the deletion path via empty jiraKey, the one-link constraint, prerequisite auth (connected Jira, edit permission), and that the change is recorded in issue history. This is the extra context the annotations cannot carry.

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 short sentences, all load-bearing: action, validation, removal path, constraints. Front-loaded with the core action; only the opening 'Say which issue...' phrasing costs a little directness.

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 two-parameter mutation with annotations already covering the safety profile and no output schema, the description covers prerequisites, validation, refusal, and removal adequately. It stops short of stating what confirmation the caller receives after a successful set, a minor 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%, so baseline is 3, but the description adds meaning: the header key identifies the target issue while 'jiraKey' is validated against the linked Jira before acceptance, and an empty value is a removal signal rather than an error. That validation semantics is not expressed in the schema.

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 concrete action (attaching the project's own Jira issue to this issue) and the accepted identifier forms, which separates it from read-oriented siblings like get_jira_link or search_linked_jira. The phrasing 'Say which issue ... this issue is' is slightly indirect, but the resource and effect are unambiguous.

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 gives clear conditions: an empty 'jiraKey' removes the link, one Jira issue per issue, and a Jira must be connected with edit permission. It does not name sibling alternatives (e.g., set_jira_connection, get_jira_link) explicitly, so routing is inferable rather than spelled out.

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