message_get

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

With no annotations provided, the description carries the full behavioral burden and does so: it discloses that the tool always fails, the exact error code, and that the response contains the replacement call. That is complete transparency for a tombstone 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?

A single, front-loaded sentence stating the migration, the replacements, and the return behavior. Every clause earns its place with no waste.

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?

Although an output schema exists, the description already explains the only meaningful return behavior (ok:false code=MIGRATED with the replacement call). For a zero-parameter migrated stub, this is fully complete.

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?

There are zero parameters, so the baseline is 4. The schema has 100% coverage and the description correctly implies no input is needed, though there is no additional parameter meaning to add.

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 states precisely what the tool now is: a migrated stub that always returns ok:false with code=MIGRATED. It names the three replacement tools (inbox_pull / inbox_peek / inbox_history), so an agent can immediately distinguish it from those siblings.

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?

It explicitly tells the agent not to use this tool and to use the replacements instead, with the condition that any call will return a MIGRATED error. No inference is required about when or whether to call message_get.

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