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Glama

Acquire Session Lease

terminal_acquire_lease

Acquire an exclusive lease for a terminal session so only one writer can perform terminal, file-transfer, or debug operations; other writers fail until the lease is released.

Instructions

Acquire one exclusive Session lease. Readers continue normally; other writers fail until release.

Input Schema

NameRequiredDescriptionDefault
typeYesExclusive operation type.
ownerYesOpaque caller-generated lease owner capability.
session_idYesActive Session ID or short reference.

Output Schema

NameRequiredDescriptionDefault
typeYes
stateYes
created_atYes
expires_atYes
session_idYes
transfer_idNo

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.4.2

TDQS

A3.7/5.0
Behavior4/5

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

Annotations already declare readOnly=false, destructive=false, idempotent=false, but the description adds the genuinely useful contention model: readers are unaffected while competing writers fail until release. It leaves out lease duration/expiry and what error the caller sees when acquisition fails, which are the remaining behavioral unknowns.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences, no filler, and the exclusivity scope is front-loaded before the contention consequence. Every clause earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema and annotations are present, so return values and safety profile need no explanation. However, for a lease-acquisition tool the description omits lease duration/expiry and whether acquisition blocks or fails immediately when contended, both of which affect correct invocation sequencing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so session_id, owner, and the type enum are already documented, including 'Opaque caller-generated lease owner capability.' The description adds no parameter-level meaning; baseline 3 is appropriate when the schema does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb ('Acquire') and resource ('exclusive Session lease'), and the word 'exclusive' implicitly distinguishes it from terminal_renew_lease and terminal_release_lease. It does not explicitly name those siblings, but an agent can tell this is the acquisition step of the lease lifecycle.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

'Readers continue normally; other writers fail until release' implies when this is needed (before exclusive write operations) and what happens if skipped, but it never says explicitly when to call it versus terminal_renew_lease or how to handle an already-held lease. Usage is inferable rather than stated.

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