credentials_delete

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

With no annotations, the description carries the full behavioral burden. It usefully discloses that the encrypted store file is rewritten without the deleted entry, which tells the agent this is a persistent mutation. However, it omits whether credentials_unlock is required, whether deletion is reversible, and what happens if the key does not exist.

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 core two sentences are well front-loaded and efficient. The trailing 'Tip: call earning_opportunities...' is unrelated to deleting a credential and adds noise without helping the agent call this tool correctly.

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 deletion tool with full schema coverage and no output schema, the description covers the basic mechanics and the file-rewrite effect. It still leaves out important call context: the likely need to unlock the credential store first, behavior when the entry is absent, and confirmation of irreversibility.

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 both parameters are already documented with examples in the input schema. The description only restates 'by service and key' and adds no format, casing, or lookup semantics beyond the schema, so 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 first sentence states a specific verb and resource ('Remove a stored credential') and the identifying fields ('by service and key'), which clearly separates it from credentials_set or credentials_get. It stops short of explicitly naming a sibling tool or its alternative, so it lands at 4 rather than 5.

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 guidance on when to use this versus credentials_list/credentials_get, no prerequisites such as unlocking the credential store, and no warning about irreversibility. The only usage-adjacent sentence is an unrelated promotional tip pointing at earning_opportunities.

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