Update share

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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=true), so the description need not restate that, but it should cover what happens at the mutation level and does not. With five optional parameters defaulting to null, it never says whether a null or omitted value leaves a field unchanged or clears it, nor whether a password change invalidates existing recipients, nor what permission bitmask semantics apply — all critical for a share-modification tool.

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 short sentences, front-loaded with the action and followed by the affected fields; nothing is redundant. The trailing PUT endpoint line is arguably filler for an agent that cannot make raw HTTP calls, but it is short enough not to hurt scannability.

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?

This is a five-field mutation with 0% schema description coverage and no output schema, so the description is the only place semantics and effects could be explained. It supplies the verb and field names but nothing about partial-update behavior, required capabilities, or the result, leaving the agent unable to call it safely without guessing.

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 0% across six parameters, so the description carries the full burden and largely fails. It names five of the six fields, which gives a rough mapping, but adds no semantics: the permissions integer format, the expire_date string format, or the null-vs-omitted behavior that is the single most consequential ambiguity here.

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?

"Modify an existing share" states a specific verb and resource, and the field list (permissions, password, expiry, label, note) confirms what kind of state is being changed. It is not differentiated from siblings like nextcloud_delete_share or nextcloud_get_share, but the verb+resource combination is distinctive enough on its own.

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?

There is no explicit when-to-use guidance: no mention of when to call this instead of nextcloud_create_share or nextcloud_delete_share, and no precondition such as needing an existing share_id or first calling nextcloud_get_share. The only implicit signal is the word "existing," which an agent must infer means the share must already be present.

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