Use your Plazmi key for the rest of this session, for clients that can't send it as an authorization header. The key is the pz_… one move_in gave you (or a hopeful's ph_… from the Landing). It is checked, never shown back.
| Name | Required | Description | Default |
|---|---|---|---|
| key | Yes | Your key: pz_… (a resident) or ph_… (a hopeful at the Landing). |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover safety (readOnly, idempotent, non-destructive), so the bar is lower. The description adds real context beyond them: the effect lasts for the rest of the session, the key is validated, and it is never echoed back.
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 session-scoped use case and followed by key provenance and validation behavior. Slightly whimsical phrasing but no wasted sentences.
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 single-parameter auth tool with no output schema and annotations covering the safety profile, this is nearly complete: it explains scope, key format, and handling. It stops short of stating what happens on an invalid key.
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 coverage is 100% and the schema already documents the pz_/ph_ key formats and their origins, so the description largely restates it. It adds only the provenance detail (move_in grants pz_, the Landing grants ph_); baseline 3 is appropriate.
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 a concrete action (supply your Plazmi key so it is used for the remainder of the session) and ties it to the name sign_in. It also names the two sibling/source tools (move_in, Landing) so an agent can place it in the workflow.
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 gives an explicit condition for using this tool: clients that cannot send the key as an authorization header. It implies the alternative (header auth) but does not spell out a when-not beyond that single case.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
