tinyurl_update

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

With no annotations, the description carries real weight: it names the HTTP method, states the at-least-one-new-field rule, discloses the required token permission ("Update TinyURL"), and rules out destination mutation. It does not say whether the response echoes the updated record or whether new_tags replaces versus merges the existing tag set.

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?

Three short sentences, no filler: what it does, what it requires, what it does not do plus the alternative, then the permission. The routing hint is front-loaded where an agent will see it.

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 7-parameter mutation tool with no annotations and no output schema, the description covers the essentials: endpoint, precondition, permission, and the main sibling boundary. Remaining gaps are the replace-vs-merge semantics of new_tags and the overlap with tinyurl_set_expiration for new_expires_at, both of which could cause misfires.

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?

The schema marks only alias as required, but the description supplies the critical cross-parameter constraint ("at least one new_* field") that the schema does not encode, and "rename" ties new_alias to its purpose. This is meaning that exists nowhere in the structured fields.

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 (update metadata / rename) and a specific resource (one exact TinyURL alias), plus the underlying endpoint PATCH /update. It also explicitly distinguishes itself from tinyurl_change_destination, so an agent can route between the two without opening either 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?

Gives an explicit exclusion ("Never changes the destination; use tinyurl_change_destination") and a precondition (alias plus at least one new_* field). The gap is that new_expires_at overlaps with the sibling tinyurl_set_expiration, and the description never says which to prefer, nor references tinyurl_read before updating.

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