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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds genuine context beyond that: the concrete endpoint mapping (GET /alias/{domain}/{alias}) and a full enumeration of returned fields, which is valuable given there is no output schema. It stops short of noting auth requirements or error behavior.

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?

Two tight sentences: purpose and returned contents first, endpoint second. Nothing is redundant and the most decision-relevant information 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 usefully compensates by listing the returned fields, and the readOnly annotation covers safety. The main remaining gap is the absence of routing guidance against siblings like tinyurl_list_links and tinyurl_get_analytics.

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%, so the schema already documents both alias and domain (including the branded-domain alternative and default). The description's endpoint path echoes the parameters but adds no format, alias-syntax, or domain-resolution detail beyond what the schema provides. Baseline 3 applies.

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 names a specific resource (one short link) and enumerates exactly what is retrieved: destination URL, tiny_url, tags, dates, flags, analytics settings, hits and owner. The word 'one' implicitly separates it from the sibling tinyurl_list_links, so an agent can tell single-retrieval apart from list operations without opening the schema.

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?

Usage is only implied by 'Details of one short link' – the agent can infer this is the fetch-a-single-record tool, but there is no explicit when-to-use, no mention of tinyurl_list_links as the alternative, and no note on how it differs from tinyurl_get_analytics despite overlapping analytics fields.

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