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

Annotations only declare destructiveHint=true; the description adds the critical qualifier that the operation is reversible via castle_unarchive_list_item, which materially softens how an agent should treat the destructive flag. No detail on permissions or whether archived items persist in other views, but the key side effect is disclosed.

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, front-loaded with the action and effect, then the reversal path. The trailing REST endpoint mapping is mildly redundant for an MCP caller but is compact and does not bloat the definition.

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, fully schema-documented mutation tool with annotations present and no output schema, the description covers what it does, its effect, and how to undo it. Only error/permission behavior is left unaddressed, which is a minor gap.

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% and both parameters (list_id, item_id) are documented there, so the description is not required to carry parameter meaning. It adds nothing extra about the parameters, so the baseline of 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?

States a specific verb and resource ('Archive a list entry') and adds the functional effect ('so it stops matching'), which goes beyond restating the name. It also distinguishes itself from the sibling castle_unarchive_list_item by naming the inverse operation.

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 a clear usage context (use it to make an item stop matching) and names the alternative path (unarchive for reversal). There is no explicit when-not-to-use guidance, e.g. archive vs. update or archive vs. delete, but the context is unambiguous.

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