add_external_link

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

The description goes beyond annotations by explaining idempotency behavior, Jira-specific validation order, canonical URL fetching, remote-link push-back with remoteLinkWarning, and failure semantics. Annotations already mark readOnlyHint=false and idempotentHint=true; the description adds concrete operational detail that an agent needs to anticipate side effects and error outcomes.

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 dense but organized: it starts with the tool's purpose and return value, then addresses idempotency and Jira-specific behavior. It is longer than typical, but every clause adds operational guidance that affects how the agent invokes the tool. The only minor inefficiency is the length, though it is mostly earned.

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?

Given there is no output schema, the description explicitly enumerates the return fields, which is essential. It also covers entrance criteria (required parameters, Jira lookup), side effects (remote link push-back), and alternatives (siblings). An agent has enough to call this correctly and predict the result.

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 high (86%), and the description adds meaningful context over the schema: it explains idempotency keyed on provider+externalId, specifies that externalUrl is required for non-Jira providers and ignored for Jira, and states which fields come from the Jira API. This goes beyond the schema property descriptions, though a few parameters like linkType are not deeply expanded.

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 opens with a specific verb and resource: 'Link any test entity to an external ticket' and explicitly enumerates the supported entity types and external systems (Jira, Linear, GitHub, GitLab). It clearly differentiates from sibling remove_external_link and list_external_links by naming them and their roles.

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 description explicitly says when to use this tool versus alternatives: 'Call list_external_links to see what an entity is already linked to and to get link ids, and remove_external_link to delete one by its link UUID.' It also gives conditional usage guidance, such as the Jira issue lookup requirement and when externalUrl is ignored.

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