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

Adds behavior beyond the annotations: it discloses the human_approval escalation path for loosening changes, enumerates which fields count as loosening (budget, autonomy, sharing, expiry, must-haves), and warns the agent never to open the approval link itself. This is meaningful operational context for a mutation tool whose annotations only say readOnly=false, idempotent=false. It stops short of covering response shape beyond human_approval and any failure modes.

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?

The first sentence is well front-loaded and the approval rules earn their place, but the final two sentences ('Not affiliated with any store, brand or platform. HaggleBoard is not a party to any sale.') are legal boilerplate that consume space without helping the agent invoke the tool.

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 mutation tool with no output schema and 0% parameter documentation, the critical approval behavior is covered, but an agent still lacks guidance on replace-vs-merge semantics, token scoping, and error conditions. Adequate but with clear gaps for a schema this complex.

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% across a large nested mandate object, so the description must carry the burden. It does add meaning for the loosening-sensitive fields and for the approval flow, but says nothing about thread_id, buyer_token, or whether omitted optional fields (target_price, walk_away, max_rounds, priorities) are dropped or preserved under 'Replace'.

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?

States a specific verb and resource: 'Replace your thread's mandate', which is distinguishable from sibling negotiation tools (make_offer, counter, accept). It does not explain what a mandate is or how full replacement differs from a partial update, but the operation itself is unambiguous.

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?

The description gives one useful usage rule — tightening applies immediately, loosening escalates to human approval — but provides no when-to-use versus siblings guidance and no prerequisites (e.g., token validity, whether the thread must be in an active state).

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