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

With no annotations, the description carries the full burden and does useful work: it discloses that passwords, TOTP secrets and codes are redacted from the reply and that cookies never leave the vault, plus the host/method enforcement. It omits error/rate-limit behavior and what a failed or blocked request looks like, keeping it from a 5.

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 dense sentences, zero filler, front-loaded with the action and followed by constraints and security behavior. Every clause carries information an agent needs before calling.

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 no-annotation, no-output-schema tool the description covers the essential prerequisites, input constraints and the security-relevant behavior of the reply. It leaves minor gaps around what the response actually contains (status/body shape) and failure modes.

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 only 20% (just body's terse note). The description does add meaning for url (https, allowed hosts), method (allowed methods) and session (must be open), which is genuine compensation. But body and headers are undocumented in both schema and description, leaving two of five parameters opaque.

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?

Clear specific verb and resource: 'Make one request inside an open session.' An agent immediately understands this sends a single HTTP request through an authenticated session, distinguishing it from open_session/end_session siblings. It does not name a sibling directly, so it falls short of a 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?

States a clear precondition ('inside an open session') and two hard constraints on inputs (https URL within the login's allowed hosts, method within allowed methods). It stops short of explicitly naming open_session as the prerequisite tool or describing when to prefer it over other ways of hitting a host.

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