paper_open_corpus

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 pinning is scoped to 'this MCP session' and that the path may be either a corpus root or a papers/ directory. However, it does not explain override behavior, validation failures, or whether a prior pin is required before other tools, leaving meaningful gaps for a stateful operation.

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 with no wasted text. The core action and accepted path forms are front-loaded, followed immediately by the usage condition.

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 simple one-parameter state-setting tool with no annotations or output schema, the description gives enough to select and invoke it: what it does, accepted path forms, and the triggering condition. It could be stronger by noting what happens if the corpus is already pinned or if the path is invalid, but it is largely 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?

Schema description coverage is 0%, so the description must compensate for the sole parameter. It adds useful domain meaning by saying 'path' may be 'a corpus root or a papers/ directory', but it does not specify whether the path should be absolute, relative, or a concrete example.

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 gives a specific verb and resource: 'Pin a corpus for this MCP session', and clarifies the accepted forms ('a corpus root or a papers/ directory'). It is distinguishable from sibling tools like paper_close_corpus by its session-pinning action, though it does not explicitly name or contrast with that sibling.

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 provides a clear trigger for use: 'when the server was launched outside the corpus.' This tells the agent the condition under which the tool is needed. It does not explicitly state when not to use it or name paper_close_corpus as the alternative, so it falls short of full routing guidance.

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